This application is filed under 35 U.S.C. .sctn. 119(e) for an invention disclosed in and claims priority of the provisional application (application Ser. No. 60/010,396) filed on Jan. 22, 1996.
The present invention is related to capillary electrophoresis, more particularly to capillary electrophoresis using a wide-bore capillary.
Capillary electrophoresis (CE) has found wide acceptance in the analytical sciences, with application in diverse fields, including pharmaceutical analysis and bioscience research. Frequently CE has been called upon to provide semi-preparative quantities for further analysis, such as for microsequencing or mass spectrometry (MS) analysis. Bundled capillaries, multiple injections combined with fraction collection, and larger capillaries have all been used with some success to provide nanomolar quantities of analytes, but these approaches have for the most part resulted in reduced performance of the CE system. Clearly the need exists for capillary separation methods to more closely match the input loading requirements of the analytical techniques with which they are mated.
An approach to increased loadability in CE is increasing the injected volume. Two methods could be used: (A) in a standard (e.g. 75 .mu.m i.d.) column (i.e., capillary), increasing the mount injected into the column, thereby increasing the injection plug length; and (B) increasing the inside diameter (i.d.) of the column (e.g., to 150.about.200 .mu.m) to keep the injection plug length constant for an increased sample loading. However, studies have indicated rapid decreases in separation efficiency when either of these two approaches are attempted.